1. Field of the Invention
The present invention relates to a valve train device for an engine capable of continuously controlling valve opening duration and the amount of valve lift.
2. Description of the Related Art
A valve train device for an engine capable of continuously controlling valve opening duration and the amount of valve lift has been practically used. Such conventional valve train device is disclosed in JP-A-Sho 59-500002, for example. This valve train device is configured to cause a camshaft to drive an intake valve to open and close through a rocker arm, in a way such that a swing member driven to swing by the camshaft is provided, and an intermediate rocker roller is interposed between a swing cam surface of the swing member and the rocker arm. Changing the position of the intermediate rocker roller causes the valve opening duration and the amount of valve lift to continuously change.
Meanwhile, when the configuration of changing the position of the intermediate rocker roller is used as in the conventional valve train device, the overall structure of the device becomes complex depending on the structure of a mechanism for of the valve characteristics is not obtained.